


why stop now

by Zekkass



Category: Marvel Cinematic Universe, The Avengers (Marvel Movies)
Genre: Alpha!Steve, Alpha!Tony, Alpha/Alpha dynamics, Alpha/Beta/Omega Dynamics, Knotting, M/M, PWP, Power Dynamics, Tony does not like to follow biological imperatives, Trope Bingo Amnesty, instincts be damned, past mentioned Tony/Pepper
Language: English
Status: Completed
Published: 2014-06-04
Updated: 2014-06-04
Packaged: 2018-02-03 09:24:39
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,577
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/1739555
Author URL: https://archiveofourown.org/users/Zekkass/pseuds/Zekkass
Summary: <blockquote class="userstuff">
              <p>Tony's an alpha, Steve's an alpha, they shouldn't work.</p>
            </blockquote>





	why stop now

**Author's Note:**

> This was supposed to be for trope_bingo (and it still is) but I missed the round so it's amnesty now.
> 
> This was also written for panpandeus, because she needed encouragement to get through schoolwork. Fingers crossed she enjoys it!
> 
> Notes: This assumes that a) Avengers are living in the tower, b) this is a nebulous post-Avengers timeline, but before IM3, Thor 2, Cap 2, and c) that both Steve and Tony are alphas in an abo world. There's a little world-building but it's mostly smut, so - please enjoy!

The elevator opens with a soft chime, revealing Tony's penthouse. His back is to the bar, a glass in his hand.

"Captain," he says, sounding sober and in command of himself, but: Steve can see the strain in Tony's face from here. Tony's throat works, but he doesn't say anything else, just swirling the drink before draining it. "Come in."

His eyes are bright, pupils dilated, and his knuckles are white on the glass.

Steve should leave. He can see the signs, but: Tony let him in, actually called him up here, and he wants to know why. Even so his eyes slide toward the elevator's panel, tempted to leave before this escalates - he's expecting it to.

The air, after all, is thick with the tell-tale scent of an alpha approaching rut. Tony should be with an omega, in his private quarters, not calling Steve up to his penthouse for a chat.

Steve leaves the confines of the elevator, approaching the bar, picking up the subtleties in Tony's scent as he approaches - the sting of alcohol, the bitter burn of desperation, nothing that makes Steve feel at ease.

"Rut suppressant," Tony says, eyes on Steve. "God's gift to alphakind, they say. What's your stance?"

Steve narrows his eyes, thinks before he answers, keeps it casual on purpose. "Could've saved me a lot of trouble back during the war."

Tony snorts, setting the glass on the bar. "No shit."

Steve doesn't want to play games, not with this topic on the table.

"Why am I here, Stark?"

"To keep me company in my misery, obviously," Tony drawls. He gets up, eyes sharpening. "I thought I'd offer you a drink first, have a chat."

"Pretend we're friends, Stark?"

"Ouch." But he's smiling, not showing teeth. "Try it before you knock it, Cap. And don't turn down a drink, I know you can't get drunk, and that's a goddamned tragedy if you ask me."

"I wasn't asking."

Tony gets to his feet, smile turning dangerous, showing his teeth. "Play along, Cap."

Steve thinks of walking out, decides against it. Tony's in a strange mood, one that he doesn't trust, and he has an unformed idea about _why_ Tony asked him here, one that he can confirm with one simple action.

He walks up to Tony, stands deliberately too close, breathes in the scent of alcohol and the pre-rut and Tony's nerves and there, there under all of that is the unmistakable whiff of arousal, something Tony probably wanted to hide.

It explains everything, and forces Steve to make some decisions very quickly, and he knows Tony knows by the time he's done breathing in.

"Life would've been _so_ much easier if you had been - " Tony starts, still in that drawl, but Steve comes even closer, eyes locked on Tony's.

"Don't finish that sentence," he says, deceptively mild. "If you want this to end without a fight, I wouldn't bring that up."

"Are you _still_ sensitive about your former size?" Tony asks. "Because I've seen pictures. Hell, I've _been_ to that exhibit on you, and - "

He doesn't get to finish before Steve's pushed him back against the bar, pressing his back to marble. Steve rumbles, low in his chest, and doesn't miss how the arousal scent spikes, or the sudden bulge pressed to his thigh. He's standing that close, holding Tony prone, hands on his shoulder and wrist.

Tony's smirking at him. Tony, he realizes, is getting exactly what he wants.

Pieces fall into place as he stands there, a hand on Tony's shoulder, another on one wrist, his face inches from Tony's, pieces he'd never put together because he hadn't thought about it, hadn't wanted to think about Tony Stark's sex life, but now?

Now it's difficult to do anything but. He growls again, low, watching Tony's reaction closely - Tony closes his eyes briefly before baring his teeth again, arousal and challenge - 

"How often did Pepper make you wear omega scent?" Steve asks, and from the way Tony stiffens he's dead-on. "Every time you two slept together?"

The world knows about that whole rocky affair, the world predicted what had come true: that Tony Stark and Pepper Potts' alpha-alpha relationship wouldn't last, not with nature working against them, even with the chemical aid of suppressants and faux-scents.

The newspapers had blamed their orientations. Steve had tried to stay out of it, but had privately come to the conclusion that it was because Pepper's patience _wasn't_ endless and because Tony's ability to aggravate and push _was._

Tony opens his mouth, but Steve covers it with a finger.

"Don't tell me. I don't want or need to know about what she did."

Tony looks up at him, eyes narrowing, before he nods. As soon as Steve pulls his finger away, he talks, which Steve should have expected. He doesn't mind, putting both of his hands on Tony's shoulders, listening to him.

"You couldn't have found out a better way to ask? Because damn, Cap, that's low - "

"You're one to talk," Steve says. He raises a hand, rubbing under his own jaw, collecting some of his own scent and rubbing his fingers over Tony's cheeks and temple, scent-marking him as his, something that would send any stereotyped alpha into a fury.

Tony growls almost automatically, but Steve feels the way his hips jerk forward against his thigh and Tony goes limp, submissive.

There's one more question before he drags Tony to the elevator.

"Tony," he says. "I'm not a one-night stand."

Tony stares at him for a long moment, then breaks out in a quick bark of laughter before lunging up to kiss him, a move that Steve doesn't stop - he turns his hold on Tony's shoulders into a pull, kissing him back, deeper - 

"Thank _god_ ," Tony says when they draw apart, both panting a little. "I was beginning to think you weren't interested - "

Steve cuts him off with another kiss, then pushes him back against the marble. "I thought you were known for being direct."

"So I wanted you to work for what we wanted," Tony says, and Steve sighs. He should have known. "Hey, now that we've established what we both want, can we get on with things? Because I don't know if you've noticed, but these pants needed to be off _yesterday._ "

"We're going to my floor first."

"Steve, that's _minutes_ away!"

"That's one of the reasons we're going there. I have questions."

"About _what?_ "

Steve lets go of him long enough to scent him thoroughly, and as Tony outright moans at the motions, Steve catches his chin.

"About _that,_ Tony. What's going on?"

"It's not obvious?" Tony asks, quirking a grin before moving to get up. Steve lets him up, but keeps a hand on his arm. "I get off on switching things up. Luckily for you."

Steve shakes his head and begins to herd Tony towards the elevator. It isn't something he can say he understands, this fetish of Tony's, but he's not one to judge. Certainly not when he intends to make the most of it.

Tony turns and kisses Steve, deep, eager, complicated Steve's movements towards the elevator.

"Tony, wait."

"I've been waiting. Cap, come on."

Steve shoves him into the elevator as the doors open, pinning him against the paneling. He takes a deep breath and gets a noseful of rut scent, of arousal, of the still-present bite of alcohol. It's a mostly welcome reminder to keep his head, because he has no idea where Tony's is, nor any idea if he's thinking with anything above the waist.

It touches on his protective instincts in a perverse way, and that keeps him from letting Tony go the entire ride down to his floor.

-

Tony looks around the suite he designed, acutely aware of Steve's hand on his shoulder and the thick smell of Steve's scent. It's heady, moreso than the alcohol, but he's got his wits - it takes a lot to put Tony Stark under the table, after all.

Besides: he's never been in Steve's suite, not after the initial tour. It's got his attention, from the little knick-knacks Steve's collected and put around the place to the thick territorial scent that's practically layered on.

Tony wrinkles his nose, glancing at Steve. "Did you mark _everything?_ "

Steve glances at him and shakes his head, steering Tony towards the bedroom, but Tony digs in his heels, arousal temporarily caught by his interest.

"No, I'm serious - was the new car smell that bad?"

"No," Steve says, tight. Tony takes a deep breath, considering this, and there - it's almost gone, that's why he missed it on the first pass, but there's the acrid tang of panic.

"Oh," he says, and now when Steve puts his hand on the middle of Tony's lower back, Tony goes. It's moving in smell, back from when Steve first moved in, and that? That's nothing he needs to talk to Steve about. Not at the cost of the impending sex.

Still - 

"You'd think a soldier wouldn't do that," he says, because he's _curious._ "The whole panic-scent-scent cycle."

"Don't," Steve says, tone threatening, and that just makes Tony contrary.

"I get it, you have a great excuse, but still, did you just spend a day rubbing on _everything?_ I don't even want to stand outside your old pad, it must have stunk to - " He's shoved to the floor, cheek pressed to the carpet, digging in with an almost painful burn, and he laughs as Steve growls about him. "Did I touch a nerve? I think you get off on this - "

He's shut up again as Steve rolls him to his back, and they stare at each other for a long quiet moment, and then Steve just sighs, beginning to get up, not offering a hand to Tony.

Tony brushes himself off when they're back up.

"You're wound up tight, Cap - take a page from Bruce's book and take a few deep breaths, come on."

"I thought you wanted me wound up."

"Right, wind you up so much you march me in there - we're still going, right?"

Steve glances towards the bedroom and back at Tony, and he nods, short.

"Great, because I really want this show to get on the road." He doesn't wait for Steve to pull him this time, instead invading Steve's bedroom like he belongs there. He looks around at the room, noting the abundance of art supplies, of knick-knacks, and of the few photographs.

He focuses on the bed, decked out in deep blue sheets and blankets with red pillowcases, a gag on his part, but one that Steve obviously hasn't bothered to do anything about. It matches the cream carpet nicely, and Tony absently rubs his cheek, wondering if he'll meet it again tonight. He wouldn't mind, but hopefully he'll meet it with the other cheek.

"You're still dressed," Steve says from behind, and Tony turns, spreading his arms.

"Casing the joint," he says with a grin. "And I thought I'd offer you the chance to tear these off yourself."

"No."

"Steve, Steve," Tony's tone turns cajoling. "If this is about the pricetag, I promise I can replace it. And get six more while I'm at it. Hell, I will buy you a dozen in your size. I am _inviting_ you to use your teeth and savor the experience, so why not take me up on it?"

"When I could watch you take your own clothes off?" Steve says, raising an eyebrow.

"Is that an invitation?"

"You tell me."

Tony decides to treat it as one, eyes on Steve as he slides his shirt off, noting how Steve's eyes stay with him the entire time. He takes his time, testing Steve's patience - or giving him a show, whichever way Steve chooses to take it - but at long last he steps back and sits on the bed, legs spread. He doesn't bother to cover up, and instead nods to Steve, whose gaze - he's pleased to notice - is still on his lap. "My eyes are up here."

"You do have a knot," Steve says, looking back up at Tony. "From the way you were acting I was beginning to wonder."

If it's a cover it's a good one. Tony bares his teeth, annoyed.

"Are you here to fight me, or are you going to fuck me?"

"You _want_ to get knotted."

"I _want_ to quit talking when you could be getting naked."

Steve wordlessly strips with a military efficiency Tony can appreciate, especially when it leads to Steve crossing the room and kissing Tony within seconds. Tony puts his hands on Steve's shoulders, then explores, eagerly mapping out skin with his fingers and answering Steve's kiss with tongue and moans. He _wants_ , and Steve's just as interested, doing his own exploration.

Steve's fingers are smooth and gentle as they trace his cheeks and chin, and as they draw apart, Steve runs his fingers over Tony's lips. It's nice, sweet even, but not what Tony wants.

He slides his own calloused fingers down over Steve's stomach and right down his narrow hips to his cock, where he traces the veins and circles his fingers under the head, feeling the weight of Steve's cock in his hand. He's hard, and from the way Steve's breathing hitches he knows he's doing the right thing.

Tony traces the base of Steve's cock with his other hand, feeling out the swelling there, the promise of a knot when Steve comes. He has to wonder how that works with the serum, especially considering an alpha's already copious amounts of come - 

but Steve kisses him hard, knocking him away from his thoughts and jerking his attention back to Steve's mouth and his hands, where they're resting _right_ next to his reactor, Steve's big hands over old scars, and Tony's first thought is always to push, to turn away, but his second is - with people he trusts - to hold still, let his partner touch and explore as much as they want.

Steve keeps kissing him and doesn't move his hands, letting Tony adjust while Steve licks at his tongue and they're both moaning, low rumbles, and with every breath Tony gets another faceful of a scent he hasn't been attracted to since Pepper -

Steve's hips jerk forward, and Tony remembers all over again that he has Steve's cock in his hands, so he goes back to that, stroking and rubbing as Steve bites at his lips, and _that_ gets a growl out of Tony, a warning that Steve doesn't listen to.

Steve just bites harder and pushes with his hands, and Tony lets go, letting Steve shove him back on the bed with Steve following him down.

"God," Tony says. "Are you ever going to do anything? I'm pretty sure I'm dying of impatience here." Bald-faced lies that he can't help as Steve reaches up, gripping his hair and dragging his head back, exposing his throat so Steve can bite at the tender skin there, gentle bites that make Tony whine.

Sounds he shouldn't be making, should never _want_ to make, but he's trained himself to, discovered that on certain levels he can enjoy going against biology, upbringing, instinct. It appeals to the ego, that defiance of the way he's built. He's Tony Stark, after all.

Steve kisses over the bites and makes his way down, kissing the reactor; Tony can tell by the dull pain the whole cavity causes when it's pressed on however lightly, he doesn't mind, letting out a soft sound, feeling more vulnerable than if Steve had tied him up and put him on display.

"Still with me, Tony?"

"Yes," Tony says it fast, tight, unable to work the nerves out of his voice. It's the reaction to anyone being that close to reactor, he knows.

Steve's face looms up into his view, visibly concerned, and Tony scowls up at him, annoyed with the whole detour.

"Don't say it, Cap," he says. "Just fuck me."

There's a crease of concern between Steve's brows, and it doesn't go away. He puts a hand on Tony's cheek. "You're sure." He's not going to do anything if Tony doesn't reveal something, and it's with an irritated sigh that Tony looks to the side and admits:

"Don't push on the reactor. It hurts."

He doesn't want pity, concern, any of that. Steve got to do as much and to go as far as he's comfortable with, more than that, but he doesn't like to admit to limits.

Steve nods, expression clearing, and Tony spots the relief before it's gone, tucked away as Steve turns his attention to what they both want: he eases back and pushes Tony's legs apart, ignoring his cock to press a finger to his hole, then in. It burns, makes Tony hiss - he has none of the natural lubrication of an omega, and he's glad for that, that's a ridiculous adaptation that he can only appreciate when he's fucking one, but - it means he has to stock his own lube.

"Nightstand," Tony gasps, and then reaches out, fumbling, when Steve just looks at him, pushing his finger deeper in. He thinks - is mostly sure - that Steve would insist on the lube, but he's not willing to find out.

He uncaps the bottle with more fumbling; tosses it to Steve who catches it and applies it to his fingers, sliding two back in without warning, making Tony jolt and cry out.

Steve scissors his fingers, hand anchored on Tony's hip, and there's nothing Tony can do except arch and grip at the sheets, wanting Steve to go _faster_ , damn it - "Steve," he gasps. " _Now_ , please."

"No," Steve says, as easy as that, and Tony drops his head back, groaning in frustration and pleasure as Steve continues to work him open. It's maddening, but it feels so good.

"Steve," he says, pleasure making him forget the nickname or any formalities. "I'm not fragile."

Steve's fingers go still, and when he lifts his head Steve's staring at him with a weirdly intense look.

He curls a finger, then slides them both out, climbing up, putting his hands on the bed, hemming Tony in close. He leans down, almost nose-to-nose with him. Tony's still, holding his breath, unsure which wire he tripped.

"You're built differently," Steve says, low, and Tony can feel Steve's cock brushing at his thigh, he's that close. It makes it hard to focus.

"So?"

"I have to treat you like glass," Steve says, eyes locked onto Tony's. "Preparation. Lubrication. I could rip you open if we weren't careful. There's no telling what more I'll hurt if I _do_ knot you, because you are _not an omega._ "

Steve's words hit him low in his belly, heat that affects his pulse. Tony can't speak, presented with that fact so baldly. Steve's going to knot him. He's going against his own biology and instincts that thoroughly, and Steve's not stopping - he's warning him.

Tony forces words out instead of a moan. "Then get through it quickly," he says, voice rough. "Don't make me wait any more."

Steve growls at him and raises a hand, shoving Tony back against the bed, a hand just above his reactor, holding him down.

"You're going to follow _my_ pace, Tony," he says, low and threatening. "Beg all you want. You're going to wait until I'm confident that I won't hurt you - or I'll leave."

Tony swallows thickly, eyes widening. "You can walk away?" He couldn't. Not if he had Steve under him and begging. His self-control - he swallows again at the image, tries to focus on Steve.

"I don't want to," Steve says. "But I won't budge on this. Understand?"

Tony nods, once, while Steve searches his expression. He nods at last and eases back, kneeling between Tony's legs again, slowly working him open again.

This time Tony moans and whimpers, but he doesn't beg him to speed up. It takes what feels like forever for Steve to stop, it must have been at least ten minutes of Steve working his fingers in and out of Tony, then a third finger and starting all over again.

He feels like he could come out of his skin as Steve pulls his fingers out, his cock throbbing against his stomach, the knot partially inflated, and he whines at the lack of sensation, all shame long gone.

"Roll over," Steve says, patting Tony's thigh. He sounds unraveled, which is good, that means his control isn't perfect, and Tony scrambles up and over, waiting on all fours, shuddering at the motion. He feels loose and empty, relaxed in all but one area, and wet besides - he has to drop his head when he realizes he feels ready for Steve in the way a proper omega would, biologically, and that's a slap of humiliation that makes his cock jerk.

Steve holds him open and Tony goes still as he feels the tip of Steve's cock push in, then the rest of it, without Steve slowing down to let him adjust. Tony groans, his shoulders tensing even as he leans back into it, understanding why Steve wanted him so loose, because it's a long burn even with that as Steve buries himself in Tony.

"Tony," Steve says above him, and nothing else. Tony can feel his hot breaths against his shoulder but he's focused on how big Steve's cock feels in him. He's whining, he realizes, and that provokes a groan, and then Steve pulls out just a little before thrusting back in, making Tony jolt and shiver all over.

Steve thrusts again, hands braced on Tony's hips, and Tony registers pain as Steve bites his shoulder, shuddering helplessly, hips twitching, not sure if he's ready to throw Steve off and bite back or if he wants Steve to thrust more, harder, faster - 

Arousal wins out as Steve drags his teeth over the bite, groaning as he does, and then he's leaning back up, the weight gone from Tony's back as Steve begins to pound into him, focused and rhythmic and Tony writhes on the bed, twisting his fingers into the sheets and shamelessly moaning.

"God, yes, Steve, please, more, I can take it please - " Steve doesn't do a thing about his begging, just keeps to his rhythm and Tony feels like he's coming apart, helpless to stop his babbling or how much he's moving and abruptly the pleasure spikes, one of Steve's hands grabbing his neck and shoving his head down against the bed and that shouldn't do anything for him except for how he can't stop moaning, and he's coming, cock jerking and making a mess on the sheets, things whiting out behind his eyes as Steve keeps thrusting.

The weight on his neck vanishes but he doesn't try to push himself back up, shaking with pleasure, mind gone hazy as he keeps thrusting - the tiny motions Steve's hold lets him take - into open air, and he could look, could look down to see the knot inflating, and it feels wrong that he doesn't even have a hand around it, but he can't get a hand down, and Steve's not helping, just pounding him into the sheets.

Things go hazy as the pleasure crests through him in another wave, and he comes to just in time to hear Steve's gasp as his own orgasm catches him. Just in time for Tony to feel the sudden pressure that's almost intolerable as Steve's knot swells up, just as big as the rest of him, locking them together and then Steve rocks forward and Tony cries out, swept back along with the heat and pleasure as the knot presses into his prostate and his legs shake, ready for him to collapse on the bed but he can't, not while Steve's holding him.

Distantly he hears Steve panting in his ear, realizes that Steve's pressed up against his back again.

"Tony," he hears. "Tony, please, I need to hear you," it's Steve, asking for something Tony has to give.

"I'm here," Tony manages, body shaking, overwhelmed by how _good_ it is and by how it's not right at all, grating on a level he can't do anything about, and that makes him burn with humiliation, that he's been knotted - he twists enough to get a hand under him, then another up so he can grab at Steve's arm.

Steve shifts them over to the side, making Tony cry out with the movement, hips trying to jerk but that only making the sensation more intense, and Steve pulls him into a tight hug, one hand around his chest under the reactor and another in his hair, smoothing it, Steve murmuring comforting words into his ear.

They lie like that as Steve works fingers through his hair, and as Tony calms down, still in the warm haze of the alpha's extended orgasm but back enough to be coherent, enough to think.

"Damn," he murmurs.

"Problem?" Steve asks, low, lips at his neck. Tony shivers.

"Opposite of one," Tony says, and he'd twist back to kiss Steve, but he can feel how _big_ Steve's knot is, and he's going to have problems sitting in the future. Especially if they do this again. He wants to do this again. "It's intense."

Steve kisses his neck, then his ear, tucking him closer. "Yeah."

Tony laughs a little, breathlessly, and he leans back into Steve, trying to find a comfortable position, but it's not working - his cock twitches every few seconds, and then Steve makes a breathy sound, and Tony bites his lip.

"Need to move?" Steve asks, voice low again.

"Yes," Tony says. "You're...big," he says, and feels more than hears Steve's laugh.

Steve shifts then over again, humming as he arranges himself on his back, an arm still wrapped around Tony, but now he's got pillows, and that changes the angle a little, enough to make Tony squirm.

"I should have known," Steve says, shuddering.

"Need me to stop?" Not that he can, really, not when it feels that good.

"No," Steve says, reaching out with one hand and finally wrapping it around Tony's cock, holding his knot carefully in his hand, making something ease in Tony's chest, letting Tony relax back into Steve's hold. "There," Steve breathes.

That's interesting, that's a reaction Tony might want to study later, but more importantly now he can settle and feel the full warmth of Steve's chest along his back and the still-too-big presence of the knot and he can slowly rock his hips up into Steve's hand and this is better, a calmer kind of pleasure where he can savor the way Steve rumbles.

Steve lets him move, sounds like he's just as pleased with his circumstances, and Tony hums, eyes sliding closed.

He doesn't sleep. He doesn't miss the way Steve kisses his neck and ear and hair. He just gets comfortable and puts his hands over Steve's, feeling trapped in a way he's comfortable with.

"Steve," he murmurs, low.

"Hm?"

"Gonna need you to do this repeatedly over the next week. Helps with rut."

"I'm not wearing any scents," Steve warns, but his tone is warm, comfortable.

"I'll fight you," Tony says, and he hears Steve laugh.

"I can take you."

Tony twists to kiss at Steve's mouth, gasping at the spike of sensation, but Steve kisses him back before he forces Tony back to his chest, holding them both steady.

"Looking forward to it," Tony murmurs, hearing _and_ feeling Steve's answering laugh.


End file.
